Timing device



Nov. 1, 1966 A. E. DILLIARD 3,282,582

TIMING DEVICE Filed April 1, 1966 INVENTOR. ALLEN E. DILLIARD BYWQ M I ATTORNEY United States Patent Army Filed Apr. 1, 1966, Ser. No. 547,684 3 Claims. (Cl. 267-1) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This application is a continuation-in-part of my copending application for Timing Device, Serial Number 349,511 filed March 4, 1964, now abandoned.

This invention relates to timing devices that provide delays or timed intervals for triggering or allowing various functions to happen at a given moment. The function being part of a sequence of actions or one action of a series of actions. The invention relates specifically to a method for providing a timed interval wherein the timing media is the creep effect of a material. Creep has been defined as the slow deformation or elongation of a material subjected to a constant stress. Creep is expressed in deformation, deflection, or displacement versus time and can be plotted accordingly. The creep of a material is also expressed as creep rate i.e., the time rate of deformation, deflection, or displacement. The creep rate has been found to be a function of stress, temperature and other environmental factors. The environmental factors (water, chemicals, etc.) can be neglected because the subject invention will generally be encased in a hermetically sealed envelope of one type or another.

The principal object of this invention is to provide a low cost timing device.

Another object is to provide a silent timing device. As creep is a noiseless phenomena this device can be used where the noise of an electric motor or escapement would be objectionable.

Another object is to provide a simple mechanism free from complex manufacturing processes or procedures.

The foregoing and other objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.

Referring to the drawings:

FIG. 1 is a view of one embodiment of the invention with one end plate removed;

FIG. 2 is a sectional view taken on the line 2-2 of FIG. 1;

FIG. 3 is an elevational view of the embodiment of FIGS. 1 and 2;

FIG. 4 is a view of another embodiment of the invention with one end plate removed; and

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4.

In the embodiment of the invention shown in FIG. 1 the creep member 1 is a rectangular solid beam, one end 8 of which abuts a spacing column 7 and the opposite end is pivotally supported by spacing column 3 passing through the eye 2 in the creep member. Centrally of the creep member 1 there is a lug 5 including an aperture for attachment of a spring 6 to apply a constant load at the center of the creep member. Opposite the lug 5 on the creep member 1 there is stop 4 which engages a projection 10 on a rotor 9 supported by rotor pivots 11 in end plates 14 and 17. A torque spring 12 provides power for driving the rotor in a counterclockwise direction. One end 13 of the torque spring 12 is fixed to the plate 14 and the other end 15 is fixed to the shoulder 16 of the rotor. Spacing column 18 in addition to spacing columns 3 and 7 maintains the end plates a fixed distance apart.

The timing device as presented in FIGS. 1, 2 and 3 is designed to turn the rotor 9 a certain number of degrees in a counterclockwise direction for a predetermined time after the device is started.

To start the timing sequence the spring 6 is extended some distance so as to place a constant load on the creep member 1. The creep member 1 will deflect or bend an initial distance almost instantaneously under this applied load. This initial deflection is called the instantaneous elastic deformation. The continuing load then causes the creep member to deflect further at a rate that is dependent upon the creep characteristics of the material of which the creep member is made. This secondary deflection has been termed the retarded elastic deformation. The amount of initial deflection is afunction of the applied load. However, the amount of secondary deflection is a function of the same applied load and time the duration of load application. Thus, the stop 4 of the creep member 1 is displaced so that the stop 10 of the rotor 9 can pass by after a predetermined period of time. The torque spring 12 then turns the rotor 9 to its new position.

Referring to FIGS. 4 and 5 another concept of timing device embodying the basic principles of this invention is shown. In this concept the creep member 1 is loaded as a column by applying a load through member 20 lengthwise of the creep member 1 which deflects or bends in a desired direction. In this concept the desired direction is away from the rotor in a plane perpendicular to the direction of the axis of the rotor. A guide 19 acting in conjunction with the end plate 17 supports the creep member so that it can deflect in the desired direction only.

In an exemplary embodiment of this invention, such as is illustrated in FIG. 1, the beam 1 can be of low density polyethylene. This means that the density is in the range .0910 to .0925. Other materials may be used for specific applications. The cross sectional dimensions of the beam 1 are .094 inch square and the distance between spacing column 3 and spacing column 7 is three-fourths of an inch. At Fahrenheit, a spring load of 20.4 ounces produces the following deflection.

Time in minutes after spring applies load: Deflection in inches It is seen that for a delay of 10 minutes, for example, the vertical dimension of the surfaces of stop 4 and projection 10 that are in contact should be .062 inch after spring load is applied.

In operation, it is optional whether to load the beam sufficiently to permanently deform the beam or to load the beam sufficiently to deform during a predetermined time and then return to be substantially at its original configuration after the removal of the load. In the latter use, the beam is said to have plastic memory by the return to its original shape. In a timing operation wherein repeated operation is desired, such as in an electric clothes dryer or other appliance, the spring load is such as to not permanently deform the beam. In other applications, such as in a delay train in ordnance devices, a loading to deform the beam permanently is of no consequence since it is destroyed after it functions. Other one time applications would likewise leave the matter of permanent deformation to choice.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A delay timing device comprising:

(a) a deformable bar pivotally supported at one end between two mutually spaced supporting plates, said bar having stop means at its opposite end;

(b) spring means for applying an approximately constant load during the timing period to the center of said bar; and

(c) a rotatable spring loaded triggering mechanism mounted between said plates and engaging said deformable bar, said triggering mechanism being released at a predetermined deformed state of said deformable bar.

2. A delay timing device comprising:

(a) a deformable bar pivotally supported at one end between two mutually spaced supporting plates; (b) stop means between said spaced plates preventing the rotation of said deformable bar;

(c) spring means applying an approximately constant load during the timing period at the center of said deformable bar;

((1) catch means on one side of said bar; and

(e) a spring loaded triggering mechanism mounted between said spaced plates, said triggering mechanism having a lug to engage said catch means of said deformable bar.

3. A delay timing device comprising:

(a) a deformable bar pivotally supported at one end between two mutually spaced supporting plates;

(b) stop means between said spaced plates preventing the rotation of said bar;

(0) means for applying an approximately constant axial compression load during the timing period at the end of said deformable bar opposite its pivotal end;

(d) catch means on one side of said bar; and

(e) a spring loaded triggering mechanism mounted between said spaced plates, said triggering mechanism having a lug to engage said catch means of said deformable bar.

No references cited. 

1. A DELAY TIMING DEVICE COMPRISING: (A) A DEFORMABLE BAR PIVOTALLY SUPPORTED AT ONE END BETWEEN TWO MUTUALLY SPACED SUPPORTING PLATES, SAID BAR HAVING STOP MEANS AT ITS OPPOSITE END; (B) SPRING MEANS FOR APPLYING AN APPROXIMATELY CONSTANT LOAD DURING THE TIMING PERIOD TO THE CENTER OF SAID BAR; AND (C) A ROTATABLE SPRING LOADED TRIGGERING MECHANISM MOUNTED BETWEEN SAID PLATES AND ENGAGING SAID DEFORMABLE BAR, SAID TRIGGERING MECHANISM BEING RELEASED AT A PREDETERMINED DEFORMED STATE OF SAID DEFORMABLE BAR. 